Printing on metal



Patented Jan. 9, 1 940 UNITED STATES ewes 146,310.. Renewed September 28,

Great Britain January 17, 1933 5 Claims. (Cl. 41-18) This invention relates to the printing of letter press and other printed characters, illustrations, maps, diagrams, ornamentations, et cetera (all hereinafter, for convenience of reference, desig- 5 nated design) in metal on a metal base, generally according to the invention described-in my prior application for patent Serial Number 705,459, filed January 5, 1934, which matured into Patent Number 2,086,069, July 6, 1937, of

which the present application is .a continuation in part thereof. In my parent application, the method of printing metal employs a suitable metal as a mask which is resistant to the subsequent electrolytic treatment whereby the platinum metal is deposited, and such metal being completely removed at a later stage of the process.

The present invention is essentially characterized in that the said metal is deposited with a finish contrasting with the finish of the metal base, and is not removed at any later stage of the process. Thus, said overlying platinum metal is deposited in a single operation with one finish over the said metal and a contrasting finish over the metal base, in order to meet any circumstance in which a contrast in finish is to be preferred to the contrast in colour effected by the invention according to said prior application for patent.

The present invention provides a method whereby an incorrodible metal is deposited in matt form upon selected portions of the surface of an incorrodible metal base, and this in such manner that the remainder of the surface of the metal base is also covered by the deposited incorrodible metal but in a contrasted finish; thus both the matt metal and the metal of contrasted finish are deposited simultaneously in a continuous unbroken surface.

40 According to one mode of carrying out my invention, a sheet (the metal base) of, say, gold alloy is taken and an imprintsay of a page of type or a halftone block) is imposed on it by any convenient photo-transfer, lithographic or other process; the sheet is then treated in a plating bath of silver or other suitable metal so that a metallic deposit is electrolytically deposited in strongly matt form upon the exposed portion or portions thereof, after which the unexposed portion of the metal base is treated by any suitable known chemical treatment or otherwise, so as to leave the portion of the gold surface beneath it exposed. The sheet is then treated in, say, a platinum plating bath, when 55 platinum is caused to be electrolytically deposited on both the exposed and metal-masked portions thereof. The sheet is now in its finished condition as a gold base bearing the design in matt platinum with a polished platinum background.

According to a modification, by transposition 6 of the early stages of the foregoing procedure, my invention may be carried out in the following manner: v

A sheet of, say, gold alloy is taken and treated in a plating bath of silver, or other suitable 10 metal, so that a metallic coating is electrolytically deposited in a strongly matt condition over the" whole surface of the sheet; then an imprint,

such as before described, is imposed on the deposited surface and the silver surface on the 15 sheet is etched down to the gold base, after which the imprint is removed by any suitable known chemical treatment, or otherwise, so as to leave the silver surface beneath it exposed; the sheet is then treated in a platinum plating bath, when 20 platinum is caused to be electrolytically deposited en both the exposed and metal-masked portions thereof. Said sheet is now in its finished condition as a gold base bearing the design in matt platinum with a polished platinum background. 5

. inum group of metals.

2. The process of printing on a gold sheet metal base, which comprises forming a mask design 40 upon the said sheet, then depositing silver in a strongly matt condition on the exposed portions of the said gold sheet metal base, then removing the mask, then plating the entire surface of the said base with a metal chosen from the 45 platinum group'ofmetals. v

3. The process of printing on a gold sheet metal base, which comprises forming a mask design upon the said sheet, then depositing silver in a strong matt condition on the mask design, then removing .themask, then plating the entire surface of said base with a metal chosen from the platinum group of metals.

4. A process of printing on a non-corrodible sheet metal base, which comprises forming upon 5;

said sheet metal base a design, of which the background is masked, then depositing a. metal in strong matt form on the exposed portions of the said base, then removing the mask, then plating the entire surface of the said base with a metal chosen from the platinum group of metals.

5. The process of printing on a gold sheet metal base, which comprises rorming upon said sheet metal base a design, of which the background is masked, then depositing silver in a strongly matt condition on the exposed portions of the said gold sheet metal base, then removing the mask, then plating the entire surface of the 5 said base with a metal chosen from the platinum group of metals.

EVERARD TUXFORD DIGBY. 

